Seek medical attention if you experience pain and notice a significant increase in the size of your left labia majora. It could be due to infections, injuries, allergies, or other conditions. 

Ulcer or pimple on vagina can be Herpes or HPV. See a doctor

Usually delay in period with sore breast is a symptomp of pregnancy. But certain matters as stress or hormone disorders or even thyroid diseases may result in late periods. Consult with your gynecologist

Toward the middle of the pregnancy, a smaller belly at 17 weeks might trouble you. If a belly is small, it can be because of the baby’s position, the way your body is holding the baby, or many other reasons. In the majority of cases, it's not a big deal when your health conditions are within normal limits. Continue to eat well and go to all of your pregnancy medical check-ins to ensure that you and your baby are healthy.

Yes definitely it is possible for a pregnancy test to show a positive result while you are approaching your menstrual period. Pregnancy tests detect the presence of the hormone human chorionic gonadotropin (hCG) in urine, which is typically produced during pregnancy. You can confirm it with another test or urine pregnancy test.